"Male birth control in the studies published actually works, as injections in the Asian male population," Dr. Sanadi said. " More studies need to be done in caucasian men, in either Europe or the United States to actually prove effectiveness. And no studies have been done in the African population."

It sounds promising, but don't expect the shot to hit stores anytime soon. It seems the folks who fund the research for the shot aren't that interested in seeing it go further.

"It's not a very lucrative market. Obviously there's a lot of ways to control male fertility in the united States," Dr. Sanadi said. " A male going once a month for an injection, it seems like something that not attractive to do."

And even less attractive, the shot, which would likely be injected into the shoulder, has some interesting side effects, including a decreased libido and more virility.